The decision has been made to put our eldest, clearly un-happy/ pained cat Mookie, down. He is so skinny and his meds are not helping he’s also like 17yrs old. However, Backpack is in the house and I don’t know how to prepare miss kitty for the passing of Mookie. Now I was thinking we should put her in my room (it’s an at home euthanasia) and I can get her afterwards but I just don’t know what to do. It’s not like they’re best friends but I don’t want her to think she’s next or that we’re mean for putting him down. I need some advice. I WISH I COULD SPEAK CAT!! HELP!!

I believe the best thinking now advocates for the living cats to actually see the body AFTER he has been put down, not during, and this is one of the reasons many people choose at-home euthanasia. Certainly you can search online to see these findings. It gives them closure.
They already know that he is old, unhappy, and in pain. They want him to be relieved of it too. It is widely believed that they are not completely shocked at death, more curious than anything. Most people believe that it is more traumatic on the living cats when the sick cat is taken away and euthanized, because it just disappears. They wait, thinking it will be back, like usual. But your kitties will not think they are "next". Just love them as you are grieving. Animals accept death better than we do.
This is what I advocate, and I am a bereavement assistant for a vet. I lead people through the euthanasia process at the vet clinic once they have decided. In any case, the vet tech who does the procedure has done it before, probably many, many times, and will advise you further and lead you through it.
Stay calm, it will all be all right, and I will be purraying for your beloved baby.

We had Natasha get her wings at the vet's. Our Alex did look for her for a week....He hasn't looked for her since the week passed. They were not close in the last couple of years because she had health problems. He is just nine while she was seventeen years. I had heard that owners have the living cats check out the one that has passed. When Natasha passed on, I stayed with her for just a short while. It breaks your heart so much but you have to realize that their burden of pain is gone. The first night is the toughest....People here were so supportive. We are here for you.....take care.....

Thank you so much. I think I'm prepared but I know I’m not. Mookie was my birthday present when I turned 4. It makes me want to cry even thinking about it. I wish I could talk to him. I feel like we’re just killing him. As for Backpack, I’m especially worried because she is barely 2, will she react any differently?

You are not killing him...You are releasing him from pain....My poor Natasha was so weary at the end. I could feel her burden release when she left. My daughter, my husband, and I were present. We held her paw. It is very quick so breathe in and then, he will be gone. I knew as soon as she left. She had gone to join my other cat, our guardian angel, Ben. I stayed with her to say my last good-bye but she had already flown to the Bridge.
Going home was so sad. I couldn't sleep that night....She slept with me by my pillow. I slept out in the living room for three days....The first week was the worst....but not for her. She was my sweetie who deserved a good-bye without too much suffering....You see that I am older than you. I saw both parents die slowly and not without much pain. Natasha deserve so much more...She like your cat has been with me for a long time.
I will see her again but not in this life. Celebrate the life and know that they enrich it....Can imagine how it may have been without them?......I grieved but I know that my memories and love aren't gone.....so I will
be ready to look for another.....so Alex, my nine will not be alone...

Alex, is my nine year old cat......Your cat will be fine....Alex went looking for Natasha in my bedroom where she was....It was hard but I allowed him to smell everything in the room. Then, my husband cleaned the room. He washed and mopped everywhere. Alex stopped looking after a week....Your younger cat will be fine...as for you, you will find comfort in time.....It is always harder on us....

You are in our thoughts, hearts and purrrrs. We lost our little Trouble just before Christmas. It was hard to watch Fluffy looking for her, and crying for her. Mourning is part of living on; for cats as well as humans...